1. The most important thing about buying a new
bike is to make sure it fits. The only way you'll know if the bike is right
for you is to size up the bike and make sure that the bike's geometry matches
your body's geometry. Ask questions and do some research.

2. If possible, try to find a shop that will
let you demo the bike on real dirt. Five minutes in a parking lot won't cut
it. You wouldn't buy a car without a real world test drive, and a bike should
be no different.

3. Don't belive the hype. Just because
your favorite rider or best friend rides a certain bike, that doesn't mean
that's the best one for you. Have an open mind and be realistic about your
needs and ability.

Biking shorts/pants

My friends and I have always laughed at the idea of me on butt hugging spandex like bike shorts and tights. I commute with a bike to work and always see people in lycra shorts...Personally I still can't wrap my head around wearing nothing but underwear. How many of you guys wear this stuff? Would it look weird to ride an XC bike with road-cycling bibs/shorts? As hotter months are coming to a close, I starting to open up to the idea of more practical cycling pants/tights, but images like the one below always comes to mind

There is a reason you see so many riders wearing lycra shorts; it's because it works and it works better than anything else. If you're insecure about the size of your concealment, don't wear red shorts. If you're still insecure then ride with a set of baggies with the lycra inserts. Be prepared to spend a bit of money because getting a good quality chamois in those shorts will be money well spent.

Don't you hate it when a sentence doesn't end the way you think it octopus?

I wear the chamois underneath, but I refuse to wear just that. So, get an outer shell, something comfortable, and rock it. This is just for my XC riding. I don't commute, although I wish that I could.

Kind of expensive...I was looking at nashbar and performance bikes and they never have mediums(my size) in stock. There's some ebay ones but I'm reluctant to pull the trigger. Anybody have any experience with these?

I have a bunch of baggy shorts with the chamois or whatever underneath. As I've lost weight I found the shorts getting a little too baggy for the past few months and it makes me want to try just the spandex but I kinda like having pockets from my baggy shorts too. Now it feels really weird to ride in anything but my baggy cycle shorts. I bought them from REI for a nice chunk of cash but well worth it in my opinion.

Ok I think I need some clearity on this subject. I see everyone say chamois.... I see this word and all that comes to mind is the towel that I used to use to dry off my truck with after washing it.

When I read all these post about chamois it sounds to me like compression shorts??

The other thing is I was looking at a pair of cardini MTN baggy that have a portion of a compression shorts sewn in them, If I was to get something like this do you just wear this and nothing underneath?

I think chamois is a term left over because chamois leather was the original material used as a liner to prevent chaffing and blisters (like leather work gloves but for your inner thighs). I've never seen leather lined shorts in person, most use synthetic materials but they still call it a chamois.
Are there shorts out there that still use leather?

Bicycle shorts are worth their weight in gold. The skintight lycra ones may look stupid, but it keeps your crotch dry and comfy. They give padding, which if you ever want to have more kids, you MUST wear them. You do not wear underwear with them...they have that liner inside that wicks the moisture away from your body.

That said, I don't have a good pair of mtb shorts yet. Right now, I just wear my Nut-hugging shorts by themselves or under some cargo shorts.

Grow up, wear the lycra shorts. You're riding a bike, thats what cyclists wear. There is a reason for it.
I tried wearing normal shorts over bike shorts or liners but gave up - why wash 2 pairs of shorts for every ride?